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| author | Kees Cook <kees+treewide@kernel.org> | 2026-09-02 15:31:14 -0700 |
|---|---|---|
| committer | Kees Cook <kees@kernel.org> | 2026-09-04 21:37:00 -0700 |
| commit | 3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d (patch) | |
| tree | c65086f9bdcd48c6360fb7cb4598bca084da1f32 /arch/x86/lib/hweight.S | |
| download | linux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.tar.gz linux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.zip | |
treewide: refresh kmalloc_obj() conversionsgrafted
This is another run of the Coccinelle script for converting kmalloc()
family of allocations to kmalloc_obj() via the existing rules in
scripts/coccinelle/api/kmalloc_objs.cocci
This catches both the set of kmalloc() uses added since the first
kmalloc_obj() conversions in v7.0 and adds a large group missed in the
first pass due to Coccinelle not interacting well with the cleanup.h
scoped_...() family of macros[1]. I worked around this with spatch's
"--macro-file" argument to a file with all the scoped_...() macros mapped
to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control
flow indicator I could find.
Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc,
riscv, and s390 with no new warnings.
Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1]
Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2]
Signed-off-by: Kees Cook <kees+treewide@kernel.org>
Diffstat (limited to 'arch/x86/lib/hweight.S')
| -rw-r--r-- | arch/x86/lib/hweight.S | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/arch/x86/lib/hweight.S b/arch/x86/lib/hweight.S new file mode 100644 index 000000000..edbeb3eca --- /dev/null +++ b/arch/x86/lib/hweight.S @@ -0,0 +1,78 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#include <linux/export.h> +#include <linux/linkage.h> +#include <linux/objtool.h> + +#include <asm/asm.h> + +/* + * unsigned int __sw_hweight32(unsigned int w) + * %rdi: w + */ +SYM_FUNC_START(__sw_hweight32) + ANNOTATE_NOENDBR + +#ifdef CONFIG_X86_64 + movl %edi, %eax # w +#endif + __ASM_SIZE(push,) %__ASM_REG(dx) + movl %eax, %edx # w -> t + shrl %edx # t >>= 1 + andl $0x55555555, %edx # t &= 0x55555555 + subl %edx, %eax # w -= t + + movl %eax, %edx # w -> t + shrl $2, %eax # w_tmp >>= 2 + andl $0x33333333, %edx # t &= 0x33333333 + andl $0x33333333, %eax # w_tmp &= 0x33333333 + addl %edx, %eax # w = w_tmp + t + + movl %eax, %edx # w -> t + shrl $4, %edx # t >>= 4 + addl %edx, %eax # w_tmp += t + andl $0x0f0f0f0f, %eax # w_tmp &= 0x0f0f0f0f + imull $0x01010101, %eax, %eax # w_tmp *= 0x01010101 + shrl $24, %eax # w = w_tmp >> 24 + __ASM_SIZE(pop,) %__ASM_REG(dx) + RET +SYM_FUNC_END(__sw_hweight32) +EXPORT_SYMBOL(__sw_hweight32) + +/* + * No 32-bit variant, because it's implemented as an inline wrapper + * on top of __arch_hweight32(): + */ +#ifdef CONFIG_X86_64 +SYM_FUNC_START(__sw_hweight64) + ANNOTATE_NOENDBR + pushq %rdi + pushq %rdx + + movq %rdi, %rdx # w -> t + movabsq $0x5555555555555555, %rax + shrq %rdx # t >>= 1 + andq %rdx, %rax # t &= 0x5555555555555555 + movabsq $0x3333333333333333, %rdx + subq %rax, %rdi # w -= t + + movq %rdi, %rax # w -> t + shrq $2, %rdi # w_tmp >>= 2 + andq %rdx, %rax # t &= 0x3333333333333333 + andq %rdi, %rdx # w_tmp &= 0x3333333333333333 + addq %rdx, %rax # w = w_tmp + t + + movq %rax, %rdx # w -> t + shrq $4, %rdx # t >>= 4 + addq %rdx, %rax # w_tmp += t + movabsq $0x0f0f0f0f0f0f0f0f, %rdx + andq %rdx, %rax # w_tmp &= 0x0f0f0f0f0f0f0f0f + movabsq $0x0101010101010101, %rdx + imulq %rdx, %rax # w_tmp *= 0x0101010101010101 + shrq $56, %rax # w = w_tmp >> 56 + + popq %rdx + popq %rdi + RET +SYM_FUNC_END(__sw_hweight64) +EXPORT_SYMBOL(__sw_hweight64) +#endif |
